The invention relates to a process and a composition for the removal of turbidity from biological fluids using surface-active substances.
In the analysis of biological fluids, turbidity caused by lipophilic substances present in the specimen often presents a problem for the photometric measurement of constituents of the specimen.
In the clinicochemical examination of serum or plasma, various attempts have therefore been made to eliminate this interference. Examples of known processes are extraction of the specimen with a water- immiscible organic liquid, precipitation of the lipid particles present in the specimen or solubilisation of the lipids. Extraction and precipitation methods require a step for preparation of the specimen and result in a change in volume of the specimen, so these techniques are unsuitable for a reliable routine analytical procedure.
For solubilisation of the lipids, surfactant mixtures have been used, the composition and action of which are described in detail in European patent 130 537. In most cases, beyond a certain triglyceride concentration and when a certain specimen/reagent ratio is exceeded, these reagents are no longer effective, so the turbidity of the specimen leads to false measurement values despite the additives in the reagent. The process described in European patent 130 537 is based on a combination of three surfactants and led to clarification of the specimen within 10 minutes, even for a high triglyceride concentration and high proportion of specimen to reagent by volume.
Thus, the art lacks a process and a simple composition for the removal of turbidity from biological fluids which effect complete dissolution of the lipid particles within a short time, even for a high proportion of specimen to reagent, without interfering with the detection reaction.